Which of these should not do when highlighting a text

You shouldn't highlight the whole text, and you shouldn't highlight things that don't have any relevance or are repetitive in the text.

Mark up the entire page

Explanation: Marking up the entire page is defeating the purpose you are highlighting. You should only mark the most important stuff.

themselves

an intensive pronoun is a pronoun that ends in self or selves, such as himself, herself, themselves, yourself, ourselves. since band members is a third person plural, the correct intensive pronoun would be themselves. if the band was talked about as a collective noun, itself would be the appropriate intensive pronoun. intensive pronouns are used to add emphasis to the noun it's modifying which is why it directly follows it.